I use PLC AB 05/04> rs232> RSLinx> Opc> AdvancedHMI. And it works well but it's poor response. When we use the push buttons and when we want to change values. Is it something to do about it.
I've tried to change the poll rate in RSLinx. But there was little difference
Use the DF1Comm driver. The native drivers are much more efficient than OPC. Be sure RSLinx is completely shut down when using DF1Comm driver to avoid the COM port conflict.
Also OPC is still considered to be in Alpha stage, so it has some known issues with writing.